Question: How was it determined that Badalona has a population of 217210?
Paraphrase: Which was the way that it was determined that Badalona has a population of 217210?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q15468 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '217210.0')) . ?s pq:P459 ?value}